Norma1 posture, balance and stable vision are dependent on interactions between the visual and vestibular systems. Our studies are directed at defining the neural substrate for normal visual-vestibular-oculomotor behavior. There is a continuous need to calibrate the motor output of the vestibular ocular reflex due to normal development or injury to the vestibular system. Without this calibration, difficulties in maintaining balance and clear vision during locomotion would occur. In addition to long-term calibration, vision is supported by moment-by-moment or dynamic visual-vestibular interactions. The neural structures involved in processing visual motion information for vestibular function are incompletely understood. Our earlier studies have shown that the pretectal nucleus of the optic tract (NOT) and the dorsolateral pontine nucleus (DLPN) receive visual information from different central structures and play a critical role in visualoculomotor behavior. Furthermore, the NOT and DLPN have efferent connections with the vestibulocerebellum and vestibular nuclei, structures known to play a role in visual-vestibular function per se. Our neurophysiological studies will define the contributions made by these important visual afferent sources to vestibular function and sensorimotor integration. Completion of our studies will be of benefit in the diagnosis and treatment of disorders of vision, balance and posture associated with vestibular dysfunction.